In our patent application WO 99/05121 we describe several derivatives of acyl-piperazinyl-pyrimidines, among which are the compounds with general formula (I), as products with sedative, anticonvulsive, hypnotic and general anaesthetic activity. In said patent derivatives are described with the general formula (I), in which R2 represents, among others, an aryl radical and a heteroaryl radical. The term “aryl” represents a phenyl radical, not substituted or substituted by 1, 2 or 3 like or different substituents, such as fluorine, chlorine, bromine, amine, acetamide, nitro, methyl, trifluoromethyl or methoxy. The term “heteroaryl” represents a heteroaromatic ring substituted or not substituted with 5 or 6 fused heteroaromatic systems or members substituted or not, of 9 to 10 members comprising 1 or 2 heteroatoms such as nitrogen, oxygen or sulphur, with the substituents being groups such as fluorine, chlorine, bromine, amine, acetamide, nitro, methyl, trifluoromethyl or methoxy.
We have now discovered that introducing a cyan group (—C≡N) in aryl or heteroaryl radicals results in new compounds with the general formula (I) which are more powerful than those previously described, having interesting biological properties which make them particularly suitable for use in human and/or veterinary therapeutics. The compounds object of this invention are useful as agents which are active in the central nervous system of mammals, including man. Specifically, the new compounds are useful as sedatives, anticonvulsives, hypnotics and general anaesthetics.